Fluorescent lamps are widely used due to their relatively low power consumption and high light output. The lamps are used in a variety of applications and in a variety of environments. In an office environment, the input voltages are typically 120–240 volts alternating current (VAC). Ballasts for fluorescent lamps typically include a power factor correction capacitor. In the case of these lower voltage applications, the capacitor can be made from a single section of metallized film.
However, in higher power applications, such as in the fluorescent and neon sign environments, there are different considerations that lead to different components being used. For example, due to the size of the signs and length of the fluorescent and neon tubes, higher voltages are required to excite the lamp gases. These voltages start in the range of 460 VAC and can be as high as 1320 VAC. The increased voltages are accomplished via step up transformers. The signs may also be located in colder temperature environments in which additional starter capacitors are required. In these high voltage applications, oil filled capacitors were generally utilized in the prior art as the power factor correction capacitors. Dry capacitors were not used because the higher voltages lead to operation of the dry capacitor in a corona manner (e.g., lead to an arcing between the capacitor plates). Therefore, oil filled capacitors were employed to reduce and/or eliminate this arcing due to the insulating properties of the oil located between the plates. However, oil filled capacitors have several drawbacks relative to dry capacitors. For example, the size of oil filled capacitors is generally limited due to fixed can sizes. The size limitation also then limits the size of the cover assembly and the distance that can be employed between the connection terminals on the cover assembly. As a consequence, the number of start capacitors is also then limited. Still further, oil filled capacitors are more costly than dry capacitors.
Therefore, there is a need in the art for a dry capacitor assembly in a higher voltage fluorescent and neon light environment without the drawback of corona arcing. Such dry capacitors can be manufactured as a wound capacitor for providing multiple capacitances in series within the single capacitor. The present invention also overcomes other shortcomings of the prior art and addresses these needs in the art.